By Jane Elliott
Health reporter, BBC News
This is becoming an increasingly common practice
The music festival season is upon us and with it come the usual health warnings.
Don't drink too much, revellers are urged; don't take drugs, drink plenty of water, wear sun screen when hot and keep your feet dry when wet to avoid trench foot.
But this year there is a new warning - to avoid or take care when 'crowd surfing'.
For the uninitiated, crowd surfing is when a person is passed over the heads of others - usually at a music concert or festival.
But medics say there are risks of injury or even deaths and are warning festival-goers to take care.
Chartered physiotherapist Sammy Margo said surfers can suffer bruises, sprains and whiplash-type injuries if dropped. She said some women had even been groped as they were passed overhead.
And the crowd are also at risk of injury if a person drops on to them or bangs into them, especially if they are wearing something sharp or heavy.
Joanna Squires, aged 30, from Essex, was knocked over and sustained bruising to her head when a man clattered into her while crowd surfing, knocking her to the ground.
Although not seriously injured, she said it did frighten her and she needed medical treatment for a panic attack.
"It happened when I was at Glastonbury and was part of a very large crowd," she said.
"It was the type of crowd that keeps swelling; the whole crowd was going backwards and forwards.
Joanna was hurt by a crowd surfer
"We were watching a band and there were some people crowd surfing and one of the guys happened to have steel toed boots on. He jumped into the crowd and bumped me on my head.
"I started to hyperventilate and had a panic attack and needed to go for medical treatment where they got me to breathe into a paper bag."
She says that anyone considering crowd surfing should think of protecting those below them.
"I think it is important that people go to festivals and have fun," she said. "But they do need to be wary crowd surfing, especially if wearing jewellery and steel capped boots. Think about other people.
Sammy Margo agreed that there were a number of things surfers could do to keep safe.
"The concern is that you get carried away by the moment - you may well be intoxicated with alcohol, drugs or the atmosphere.
"Crowd surfing is not ideal but if it is going to happen you must try to do it safely.
• Wear clothes that don't have sharp edges such as zips or studs. Wear soft shoes
• Don't have any valuables on you, as they can fall out or be stolen
• Avoid wearing piercings or chains as they can easily get caught on clothing
She said relaxing also helps lessen the severity of falls, minimising sprains, whiplash injuries and bruising.
"If you are accidentally dropped, try to relax into the fall instead of tensing up," says Sammy. "You'll be more supple and less likely to fall awkwardly and injure yourself."
Deborah Rees, founder of the Safeconcerts website, said that few studies had been undertaken to see how many people were injured at concerts.
But she said that one recent report by a student asking random festival goers about their injuries showed that out of 40 he spoke to, 30 said they had been hurt at some event they attended, many through crowd surfing.
And a report by Airedale NHS trust in 2000 showed that at one three-day music festival in August 2000, with 60,000 people a day attending, there were 43 minor crowd surfing injuries.
Crowd surfing - being passed around above the crowd's heads, with everyone's hands supporting you
Stage diving -launching yourself from the stage and hoping the crowd will catch you and let you surf
Deborah said there had however been fatalities since, such as the death of Patrick Sherry (front man from Bad Beat Review) who died after diving from the stage into the crowd in 2005.
But she said banning crowd surfing and stage diving however might just encourage it even more.
"The more you try to ban it, the more attractive it becomes," she said.
"One of the best things is to educate yourself. I do not like telling people what they can and can't do because you are on a hiding to nothing, but what people need to think about is the impact on people around them.
"I think rather than banning it you should have an area where they can do it safely."